1. Field of the Invention
The present invention relates to an improvement of a steering column supporting apparatus for supporting on a car body a steering column constituting a steering device of an automobile, and to a steering column supporting apparatus capable of reducing costs by decreasing the number of parts and the number of assembly processes.
2. Related Background Art
FIGS. 27-29 show one example of an automobile steering apparatus which has hitherto been known. A motion of an unillustrated steering wheel is transmitted to a steering gear which is not likewise illustrated via a steering shaft 36 and an unillustrated universal joint, thereby imparting a steering angle to front wheels. Further, the steering shaft 36 is rotatably supported inside a steering column 6 supported on a car body. This steering column 6 is fixedly supported through a support bracket 38 and a supported bracket 39 on a fixed bracket 37 fixed by welding to a cross member 1 provided on the car body.
The support bracket 38 is fixedly connected to the fixed bracket 37 by use of bolts 40, 40 and nuts 46, 46. The supported bracket 39 is fixedly connected by welding to an intermediate portion of the steering column 6. Then, the supported bracket 39 is fixedly connected to the support bracket 39 by use of a bolt 11 and a nut 12.
Note that the example illustrated therein shows a shock absorbing tilt type steering apparatus given a shock absorbing function of absorbing a shock applied to a body of the driver who has collided with the steering wheel when at a secondary collision, and a function of making adjustable of a height position of the steering wheel. A contrivance of providing the shock absorbing function thereof involves the use of a collapsible steering column 6 of which an entire length is reduced while absorbing an impact energy. In addition, a supported bracket 39 is so supported by a support bracket 38 as to be detachable therefrom when a strong force acting forward (leftward in FIG. 2) is applied.
A front side end (a left side end in FIG. 27) of the steering column 6 is supported on a car body 42 in a rockable manner about shafts 41, 41. To be specific, a rock bracket 44 fixed by welding to the front side end of the steering column is pivotally supported through the horizontal shafts 41, 41 by a lower fixed bracket 43 fixed to the car body 42 with a bolt. Further, the bolt 11 engages with an elongate hole 45 formed in the support bracket 38 and taking a circular arc with the horizontal shaft 41 being centered. Note that a structure of the shock absorbing tilt type steering apparatus, which has hitherto been known, is not related to the gist of the present invention, and hence a detailed description thereof is omitted.
The prior art structure described above requires a large number of parts needed for supporting the steering column on the car body, which inevitably leads to a rise in terms of costs. Namely, the prior art structure requires at least "the fixed bracket 37", "the support bracket 38", "plural pairs of bolts 40, 40 and nuts 46, 46 for connecting the fixed bracket 37 and the support bracket 38 to each other".
It is therefore inevitable that a parts working cost, a parts management cost and an assembly cost rise due to an increase in the number of parts, which might induce a rise in the costs for automobile steering apparatus including a steering column supporting apparatus. Further, it is required that the plural pairs of bolts 40, 40 and nuts 46, 46 for connecting the fixed bracket 37 and the support bracket 38 to each other, be disposed, as obvious from FIG. 28, at a large pitch to some extent in terms of how much a tool for fastening the bolts 40, 40 and the nuts 46, 46 can be handled. Consequently, there arises a necessity for setting width dimensions (right-and-left directional dimensions in FIG. 28) of the fixed bracket 37 and of the support bracket 38 larger than substantially needed, with the result that the steering column supporting apparatus is downsized and reduced in weight with a difficulty.